A margin agreement is the contract you sign to open a margin account, and it does four things at once: it lets you borrow money from the broker to buy securities, pledges everything in the account as collateral for that loan, gives the firm the right to sell your holdings without warning if your equity falls too low, and routes any future dispute into arbitration instead of court. Before signing, it’s worth understanding exactly what each of those permissions allows the broker to do.
What You Are Actually Signing
Most margin agreements bundle three components, sometimes in one document and sometimes as separate signatures.
The credit and hypothecation agreement establishes the loan. It sets how much you can borrow, the interest rate, and the collateral securing the debt. Every security in the account is collateral, including shares you paid for entirely in cash.1SEC.gov. Investor Bulletin: Understanding Margin Accounts
The loan consent authorizes the firm to lend your securities to other investors, usually for short selling. This is the one piece you aren’t legally required to sign, though most brokers will decline to open the account without it. When your shares are out on loan, you can lose your right to vote them and may receive payments in lieu of dividends rather than qualified dividends, which changes their tax treatment.
The third component is a set of risk disclosures the firm must provide before or when you open the account. These aren’t boilerplate. They summarize, in plain language, the rights the legal clauses grant the firm.
The Rights You Grant the Broker
Hypothecation is the mechanism that makes the whole arrangement work. When you sign, you grant the firm a security interest in every asset in the account. Your securities become collateral. The firm doesn’t own them, but it holds a legal claim it can enforce if you fail to repay the loan or meet a margin call.
The agreement also authorizes re-hypothecation, meaning the firm can pledge your securities to a bank as collateral for its own borrowing. That is how broker-dealers fund the margin loans they extend. Federal law limits the practice: under SEC Rule 8c-1, a firm cannot pledge customer securities under liens that exceed the aggregate indebtedness of all customers whose securities are being pledged, and it cannot commingle your securities with the firm’s own inventory under any pledge without your written consent.2GovInfo. 17 CFR 240.8c-1 – Hypothecation of Customers’ Securities
You keep the economics of ownership. Dividends, voting rights on shares not out on loan, and gains still belong to you. The broker controls custody and can use the shares as collateral. That separation between ownership and control is one of the less obvious tradeoffs of the agreement.
How Much Equity You Have to Keep
Three layers of rules govern how much of your own money must sit in the account. Falling below any of them triggers a margin call.
Initial Margin Under Regulation T
The Federal Reserve’s Regulation T sets the initial margin requirement at 50% of a security’s purchase price for most equity securities. To buy $20,000 of stock on margin, you deposit at least $10,000 of your own money. Some firms require more for volatile or thinly traded securities.3eCFR. Part 220 – Credit by Brokers and Dealers (Regulation T)
Maintenance Margin
After the purchase, your equity must stay above a minimum percentage of the current market value of your holdings. FINRA Rule 4210 sets the regulatory floor at 25% for long positions, but the rule is genuinely just a floor. Most firms set house requirements between 30% and 40%, and Rule 4210 itself encourages them to set higher requirements on individual securities or accounts they consider risky.4FINRA. FINRA Rule 4210 – Margin Requirements
Concentrated positions face steeper requirements. Under Rule 4210, control and restricted securities that represent more than 10% of a company’s outstanding shares carry maintenance requirements that scale upward in tiers, reaching 100% of market value once concentration hits 30% or more of outstanding shares.4FINRA. FINRA Rule 4210 – Margin Requirements
House Rules Can Change Without Notice
Regulation T expressly permits exchanges, FINRA, and individual broker-dealers to impose additional requirements beyond the regulatory minimums.3eCFR. Part 220 – Credit by Brokers and Dealers (Regulation T) During a volatile stretch, a firm can raise its house requirement from 30% to 50% overnight. That single change can trigger a margin call in an account that was fully compliant the day before, even if your holdings haven’t lost a cent.
How Margin Interest Works
Interest accrues on your outstanding loan balance, called the debit balance. Brokers typically start with a benchmark known as the broker call rate (the rate banks charge brokers for margin lending) and add a spread that varies by firm and account size. The rate is variable and fluctuates with market conditions. Interest compounds and posts to your account whether your investments gain or lose value, so a losing position costs you the loss plus the interest that accumulated while you held it.
Margin Calls and Forced Liquidation
This is where the agreement matters most. A margin call happens when your account equity drops below the maintenance requirement, whether that’s the FINRA 25% floor or your broker’s higher house requirement. If your positions lose enough value, the loan becomes under-collateralized, and the firm demands more equity.5FINRA. Know What Triggers a Margin Call
The firm’s response is what catches most investors off guard. The margin agreement grants the broker the right to sell any securities in your account to bring equity back above the required level. The firm doesn’t need your approval, doesn’t have to call you first, and can choose which securities to sell and at what price. The agreement gives the broker sole discretion. If the sale proceeds don’t cover the full debit balance, you are personally liable for the remaining deficit.1SEC.gov. Investor Bulletin: Understanding Margin Accounts
The Arbitration Clause
Nearly every margin agreement contains a predispute arbitration clause, governed by FINRA Rule 2268. Signing waives your right to sue the firm in court and commits you to binding arbitration, usually administered by FINRA’s own dispute resolution forum. You also give up the right to a jury trial and, in most cases, the right to participate in a class action related to the account.6FINRA. FINRA Rule 2268 – Requirements When Using Predispute Arbitration Agreements for Customer Accounts
Arbitrator decisions are final and binding, with narrow grounds for appeal. If you believe the firm mishandled a margin call or liquidated your account improperly, arbitration is almost certainly the only path to recover losses.
What Cannot Be Bought on Margin
Not everything in a brokerage account can be purchased with borrowed money, and the margin agreement doesn’t override that. Regulation T defines which securities qualify as marginable, and anything outside that definition requires 100% cash. Eligible categories include securities listed on a national exchange, Nasdaq-listed securities, registered mutual funds and unit investment trusts, non-equity securities like bonds, and certain foreign stocks meeting specific criteria.3eCFR. Part 220 – Credit by Brokers and Dealers (Regulation T)
Over-the-counter stocks not listed on Nasdaq or a national exchange, penny stocks, and newly issued securities that haven’t traded long enough typically cannot be margined. OTC stocks that aren’t already on the marginable list must have been publicly traded for at least six months before they become eligible. Firms may also designate specific securities as non-marginable based on their own risk assessment even when federal rules would allow it.4FINRA. FINRA Rule 4210 – Margin Requirements
The Required Risk Disclosures
FINRA Rule 2264 requires the broker to give you a written margin disclosure statement before or at the time the account opens. The five points below restate, in plain terms, what the legal clauses of the agreement actually let the firm do:
- You can lose more than you deposit, and you are personally responsible for the shortfall.
- The firm can sell your securities without contacting you first. It isn’t required to issue a margin call, though many firms attempt to as a courtesy.
- The firm can raise its house margin requirements at any time, without advance notice, and isn’t required to grandfather existing positions.
- You cannot choose which securities are sold to meet a margin call. The firm decides what goes and at what price.
- You are not entitled to a time extension. Even if the firm offers one, it can still act immediately without waiting for a deposit.
These disclosures exist because margin accounts have historically produced significant investor losses. The clauses aren’t hypothetical worst cases. Brokers exercise these rights routinely during market downturns.7FINRA. Margin Regulation
What the Agreement Doesn’t Protect You From
SIPC coverage protects customers if the brokerage firm itself fails, up to $500,000 per customer including a $250,000 sublimit for cash. For a margin account, SIPC calculates your net equity by subtracting the outstanding margin loan balance from the total value of the account. An account holding $400,000 in securities with a $150,000 debit balance has net equity of $250,000 for SIPC purposes. SIPC does not cover market losses or the decline in value of securities you bought on margin.8SIPC. What SIPC Protects